The present invention relates to signal pick-up apparatus for reproducing recording discs, and more particularly to a pick-up cartridge which is detachable from a pick-up apparatus structure. There is a structure for accommodating a reproducing stylus within the interior of the cartridge without deformation of a stylus pressure exerting member. The reproducing stylus is brought into contact with the recording disc at a predetermined stylus pressure when the pick-up cartridge is loaded in the apparatus structure.
In general, an apparatus reproduces an information signal by tracing a record groove, with a reproducing stylus. The information signals have been previously recorded in high density in the grooves. The structure including the reproducing stylus is incorporated within a cartridge which may be detachably loaded into the pick-up apparatus so that it may be replaced when the stylus wears out.
The cartridge known heretofore includes a cartridge casing containing a pick-up arm and a elastic damper material for exerting a stylus force responsive to an elastic deformation. Particularly, the elastic material is interposed between the inner wall of the casing and the pick-up arm. Accordingly, when the cartridge is not used or is not loaded in the pick-up apparatus structure, the elastic damper material is compressed to accommodate the reproducing stylus within the cartridge casing, thus protecting the reproducing stylus from unexpected damage. After a long period in an unused state, the damper will have deformation even when the compression force for the elastic material is released by loading the cartridge into the pick-up apparatus structure. Therefore, difficulties arise since the normal stylus pressure can not be exerted upon the stylus and the dynamic signal detection characteristic deteriorates, in the extreme.